Feed mechanism for machine-tools.



No. 829,800. PATENTED AUG. 28', 1906.

'E.- PETERS. FEED MECHANISM FOR MACHINE TOOLS. APPLICATION FILED D110.20. 1906.

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FEED MECHANISM FOR MACHINE-TOOLS.

Specification of Letters Patent.

Patented Aug. 28, 1906.

Application filed December 20,1905. Serial No. 292,651,

To (LIZ whom it may concern:

Be it known that I, ERNST PETERS, a subject of the German Emperor, and'a resident of Dusseldorf, Germany, have invented certain new and usefulImprovements in Feed Mechanism for Machine-Tools, of which the followingis a specification.

My said invention relates to improvements in machine-tools in which thefeed of the cutter is effected by some moving part of the machine; andthe object of the invention is to provide a simple, durable, andefficient construction in'which the feed is automatically controlled bythe variations in the resistance which the work offers to the tool orcutter.

l/Vith these and possibly other objects in view the invention includesthe novel features of construction and arrangement and combinations ofparts hereinafter described, and particularly pointed out in theappended claims.

The invention is illustrated in the-accompanying drawings, in whichFigure 1 is a sectional elevation. Fig. 2 is a detail side view of partsshown on the right of Fig. 1, and Fig. 3 is a longitudinal sectionaldetail of the same on a slightly larger scale. Fig. 4 is a detailsectional view taken transversely of Fig. 3. Fig. 5 is an elevation of amodified form. Fig 6 is a transverse sectional view of the form shown inFig. 5. Fig. 7 is a diagrammatic view of a further modification; andFig. 8, a detail view of a further modification, disclosing the use ofpinions instead of worm-gearing.

Referring first to the form shown in Figs. 1 to 4, the referencecharacter a designates the tool, which for convenience is shown as ametal-cutting saw mounted upon a shaft b, j ournaled in suitablebearings depending from or carried by a part g, which has a shank g,held in an opening in the end of the toolslide, which is slidablysupported in the main frame d. A drive-shaft f is journaled at one endin the tubular shank or portion g and carries a worm c, which mesheswith a wormwheel a on the shaft b, whereby the cutter a is driven by therotation of the shaft f, which is driven from any suitable source ofpower in the manner hereinafter described. The opposite end of the shaftprojects into a sleeve (1, journaled in the end wall of the tool-slide,said parts f and 9 being connected by a longitudinal spline connectionwhereby they are capable of longitudinal movement with rela tion to eachother, but are non-rotatably connected. Fast and loose pulleys 11 and 12are connected to this sleeve for driving the shaft f. It will thus beseen that while the shaft f will be rotated by the fast pulley it willbe capable of movement longitudinally without disturbing its operatingconnections. The shaft f is normally held pressed toward the right by aspring h, which encircles the shaft between the part g and an adjustablecollar h on the shaft.

The sleeve g carries a collar 7c, rigidly secured thereto in a recess inwhich is mounted a bell-crank lever i, one arm of which engages a recessin the shaft f, as shown in Figs. 1 and 3, while the other arm enga es asimilar recess in a slide-block Z, movabiy held in adiametrically-arranged groove in the outer face of the collar 70. Thisslide Z carries a wristpin m, to which is pivoted a pawl 0, engaging theratchet-teeth of a wheel a. This wheel n is rigidly secured to a shaft1), which has a threaded portion engaging a corresponding threadedopening in the frame (1. A bracket or arm 6 depending from the slide .2;and having a suitable rotatable but non-longitudinally-movableconnection with the shaft or spindle 1), causes the movement of saidspindle, due to the rotation of the ratchetwheel a, to be imparted tothe slide to advance the cutter to its work. It will be readily seenthat if the slide Z is moved inward to bring the wrist-pin nearer theaxis of the shaft f the eccentricity of the wrist-pin will be decreased,and consequently the throw of the pawl and the movement of theratchet-wheel correspondingly lessened, retarding the feed of thecarrier or slide a, while the opposite movement of the slide Z willincrease the eccentricity of the wrist-pin and the feed will beincreased. This movement is automatically controlled by the resistanceof the work to the tool or cutter through the connections hereinbeforedescribed in the following manner:

Supposing the work to offer so great resistance as to tend to retard thespeed of the cutter, the worm c and shaft f would be moved to a greateror less extent in the direction of the arrow y against the tension ofthe spring h. This movement, through the bell-crank a} and slide Z,reduces the eccentricity of the wrist-pin and lessons the feed, ashereinbefore described. As soon as the resistance of the work to thecutter lessens the spring moves the shaft f and worm to the right,increasing the feed again.

In the mo dification shown in Figs. 5 and 6 the worm-shaft (designated fcarries a fixed wrist-pin s, which imparts a constant throw to the pawlto rotate the feed-ratchet n. A bell-crank lever 12, pivoted on an arma, has one arm arranged to bear against the cone 1' and its other armprovided with a pin w to engage with the pawl w. The pawl in this caseis carried by the oscillating lever t, and it will be readily apparentthat longitudinal movement of the shaft f will cause the cone 1" to rockbell-crank lever Q), and through pin 10' make a greater or less portionof the stroke of the pawl ineffective.

In the modification shown in Fig. 7 I dispense with the use ofpawl-and-ratchet mechanism for effecting the feed, using frictiongearing2 3 to drive the feed-screw 79 and controlling the feed by shifting thefrictionpulley 2 by a bell-crank 1 through the endwise movement ofworm-shaft f In the modification shown in Fig. 8 I show how ordinarygearing may be substituted for the worm-gearing shown in Fig. 1. In thisform the drive-shaft f 3 has a spirally-threaded portion on which ismounted a gear 4, which, through a corresponding gear 5, operates thecutter.

Having thus described my invention, what I claim is 1. In a machine ofthe class described, the combination, with a rotary cutter and apower-transmitting gearing arranged to drive said cutter and embodyingspiral coacting members, one of which is axially yielclable whereby anaxial thrust of the yieldable spiral member is produced, of feedingmechanism for causing a relative ap proach of the work and cutter, avariablespeed transmission. device for actuating the said feedingmechanism, and means intermediate the whereby the ratio of transmissionof the latter will be adjusted. in proportion to the power-transmittinggearing and the variable-s cod-transmission device thrust produced bythe spiral coacting mem' bers.

2. In a machine of the class described, the combination, with a rotarycutter, a rotata ble driving-shaft arranged to move longitudinally whensubjected "to axial thrust, a power-transmitting gearing having spiralcoacting members arranged to transmit power from the driving-shaft tothe cutter and to transfer the reaction of the cutter to thedrivingshaft as an axial thrust upon the latter, yielding means actingupon the driving-shaft in opposition to the said axial thrust, and afeeding mechanism for causing a relative approach of the work andcutter, of a variable-spcod-transmission device for driving said feedingmechanism, and means actuated by the longitudinal movement of thedriving-shaft for adjusting the variablespeed-transmission device,whereby the rate of relative approach of the work and cutter is varied.

3. In a machine of the class described, the combination, with a rotarycutter, a rotatable driving-shaft arranged to move longitudinally whensubjected to axial thrust, a

-power-transmitting gearing having spiral coacting members arranged totransmit power from the driving-shaft to the cutter and to transfer thereaction of the cutter to the driving-shaft as an axial thrust upon thelatter, yielding means acting upon the driving-shaft in opposition tothe said axial thrust, and a feeding mechanism for causing a relativeapproach of the work and cutter, of a variable-speed-transmission deviceintermediate the driving-shaft and the said feed mechanism, and meansactuated by the longitudinal movement of the driving-shaft for adjustingthe ratio of transmission of the variable-speed-transmission device.

In testimony whereof I have hereunto signed my name in the presence oftwo witnesses.

ERNST PETERS. itnesses: WILLIAM ESSENWEIN, PETER Linnea.

